Traveling offset web controlling mechanism for multicolor printing presses



H. M. BARBER Aug. 1, 1933.

TRAVELING OFFSET WEB CONTROLLING MECHANISM FOR MULTICOLOR PRINTING PRESSES Filed July 1, 1931 INVENTOR flwmd m ATTORNEYS Patented Aug. 1,1933

' TRAVELING OFFSET WEB CONTROLLING IMECHANISM .FOR MULTICOLOR PRINT- ING PRESSES Howard'..M. Barber, of Pawcatuclr, Conn., as-

signor' to C. B. Cottrell & Sons Company, of Westerly, R. 1., a Corporation of Delaware .7 ApplicationJuly 1, 1931.1 .Serial No. 548,137

' 15 Claims. (01. 101-417) It has been very diiiicult in multicolor web perfecting'rotary printing presses to obtain'clean and sharp printing because of the tendency of slippage between the offset web and printed web i as they are passing around the impression cylinder of the second printing unit.- This waspointed out inmy United States Letters Patent No. 1,806,141, dated May 19th; 1931, and an'ofiset web controlling mechanism for obviating this fault was disclosed and claimed therein.

The object of this present invention is to 'ensure clean and sharp printing by providing an offset web controlling mechanism which engages the traveling offset web both before and after it passes through the second printing unit and acts to exert tension tending to slightly retard the offset web, thus eliminating slippage between the webs as they pass around the impression cylinder of the second printing unit.

My invention more particularly includes an offset web controlling mechanismhaving a positively driven web tension element engaging the offset web before it passes around the impression cylinder of the second printing unit and another -positively driven web tension element engaging theoffset web after it leaves the impression cylinder and before'it reaches the offset web rewinding mechanism.

My invention alsoincludes a manually controlled variable-speed 'drive for the offset web control mechanism for regulating the speed of the offset web,- said variablespeed drive being itself drivenfrom the printing unit.

A practical embodiment of my invention is represented in the accompanyingdrawing in which:

Fig. 1 represents a diagrammatic side elevation of that portionof a multicolor web perfecting rotary printing press which embodies my invention; and Y 1 i Fig. 2 represents a detail toplpl an view showing the variable speed drive unit for the offset web controlling mechanism.

In the printing press illustrated, four form cylinders 1, 2, 3, 4 are represented as driven from and coacting withthe impression cylinder 5. The traveling printed web is denoted by 6 and the traveling offset web by '7, 'which offset web'is shown as leading from the supply roll 8 around the impression cylinder 5 to the take-up roll 9 of theoifset web rewinding mechanism.

This rewinding mechanism in the present instance is shown as comprising a pair of rollers 10, 11, driven from the gear 12- on the shaft of the impression cylinder 5 through'the train of gears 13 to 21 inclusive.

The offset web controlling mechanism is herein shown. as comprising three positively driven offset web tension rolls 22, 23, 24. The oifsetweb I as it leaves its supply roll 8 passes to and'around a roller 25 and from thence back and around the web tension roll 22 of the offset web controlling mechanism.-. From thence the offset web passesaround the rollers 26, 27 to and'around the imr pression cylinder 5. From thence the offset web 5 0 passes around the rollers 28, 29 to and around the web tension rolls 23, 24 of the offset web controlling mechanism. From the web tension roll 2a the. offset web passes around the rollers 30, 31, 32 to the offset web take-up roll 9.

The web tension rolls 22, 23 and 24 of the offset web controlling mechanism are driven at the same surface speed through the intermeshing gears 33, 34, 35. These web tension rolls are positively driven from a manually controlled variable speed drive such as the well 'known Reeves drive in. which the shaft 36 is driven at a constant speed by the meshing of its gear'37 with the gear 19 of thetrain of gears leading from the second printing unit to the offset web rewinding mechanism. The shiftable cone pulleys 38 on the constant speed shaft 36 'drive the shiftable cone pulleys 39 on the shaft 40 through the usual belt 41. This shaft 40 drives the shaft i1 of'the retarding roll 23 through the chain and sprocket connection 42, 43 ,44. The manually operated means for varying the speed of. the shaft 40 is denoted as a whole by 45.

' The printed Web is taken off from the impression cylinder 5 by the roll 46 whose gear 4'7 is driven from the gear 14 of the train of gears leading from the impression cylinder gear 12 to the offset Web rewinding mechanism.

I have found that by providing the offset web controlling mechanism" with positively driven web tension elements engaging the oifset web before and'after it passes around the impression cylinder of the second printing unit the offset web is effectively controlled sothat there will 40 x before and after it passes through the printing unit, to exert tension tending to slightly retard ing to slightly retard the Web. I

product.

The. linear speed of the offset web is controlled be no slippage between it and the printed web as they pass around the impression cylinder, thus ensuring the clean and sharp printing of the by the offset web tension rolls 22, 23 and 24 and not by the surface speed of the impression cylinderlli. These offset web tension rolls 22, 23 and 24 have the same surface speeds, which speeds ment of the several parts Without departing from the spirit and scope of my invention, and hence I do not intend to be limited to the particular embodiment herein shown and described, but 0 What I claim is:

printing press, a printing unit, a traveling oifset web, its rewinding mechanism, and an offset web controlling mechanism engaging the offset. web, both before and after ittpasses through the printing-unit, to exert tension tending to slightly retard the web. v 2, In a multicolor web perfecting rotary printa ing press, a printing unit, a traveling offset web, its rewinding mechanism, and a positively driven Offset Web controlling mechanism engaging the offset web both before and after it passes through the printing it, to exert tension tend- 3. In a multicolor web perfecting rotary print ing press, a printing unit, a traveling-offset web, its rewinding mechanism, and an offset web controlling mechanism engaging the' offset web both including a variable speed drive.

4. In a multicolor web perfecting rotary printing press,'a printing unit, a traveling offset web, its rewinding mechanism; and a positively jdriven offset web. controlling mechanism engaging theoifset web, both before and after it passes through the printing unit, to exert tension tend:

the web, said offset Web' controlling mechanism ing, to slightly retard the web, said offset web controlling mechanism including a variablespeed drive.

5. In a multicolor web perfecting rotary print: ing press, a printing .unit, a traveling offset web,its rewinding mechanism, and an offset web controlling mechanism engaging theoffset web both before and, after it passes through the printing unit, to exert tension tending to slightv 1y retard the web said offset web controlling mechanism including a manually adjustable variable speed drive.

6. In a multicolor web perfecting rotary print- .ing press, a printing unit, a travelingoffset web, its rewinding mechanism, andapositively driven offset-web controlling mechanism engaging the offset web both before and after ,it passes throughthe printing unit, to exert; tension tending to slightly retardftheweb, said offset web controlling mechanism including a manually adjustable variable. speed drive.

, 7. In a multicolorwebperfecting rotaryprinting press, a printing unit, a traveling offset web, its rewinding mechanism driven from the printingunit, and an olfset .webcontrolling mechao v unit. I It is evident that various changes maybe resorted to in the construction, form and arrange- 1 nism also driven from the printing unit and engaging the offset web both before and after it passes through the printing unit, to exert tension tending to slightly retard the web.

8. In a multicolor web perfecting rotary printing press, a printing unit, a traveling offset web, its rewinding mechanism driven from the printing unit, and an 'oifset web controlling mechanism also driven from the printing unit and ennism' also drivenfrom the printing unit and engaging the offset web both before and after it passes through the printing unit, to exert ten- 1. In a multicolor web perfecting rotary sion tending to slightly retard the web, said olfset web controlling mechanism including a manually adjustable variable speed drive also driven from the printing unit. i V

10. In a; multicolor" web perfecting rotary printing press, aiprinting unit, a traveling offset web its rewinding mechanism, and an offsetweb controlling mechanism having a positively driven element engaging the offset web before. it passes through the printing unit and another positively driven element engaging, the offset web after it leaves the printing unit, to exert tension tending to slightly retard the web. ll. In a multicolor web perfecting rotary printing press a printing unit, a traveling offset web, its rewinding mechanism, and an offset web controllingmechanism having a positively driven element engaging the offset web before it passes through the printing unit and another positively driven element engaging theoffset web after it, leaves the printing unit, to exert tension tending to slightly retard the web, said offset Web controlling mechanism including a variable speed drive, I i I 12. In a multicolor web perfecting rotary printingpress, a printing-unit, a traveling offset web, its rewinding mechanism, and an offset web controllingmechanism having a positively drivenelement engaging the oifset web before it passes through the printing unit and another positively driven element engaging the offset web after it leaves the printing unit, to exert tension tending; to slightly retard the web, said offset web controlling mechanism including a manually adjustable variable speed drive.

.13; In a multicolor web perfecting rotary printing press, a printing unit, a traveling offset web, itsrewinding mechanism, and an offset web controlling mechanism having a positively driven roll around which the offset web passes'before reaching the printing unit and other positively driven rollsaround which the offset web passes after it leaves the printing unit, to exert tension tending to slightly retard the Web.

1am a multicolor web perfecting rotary printing press, aprinting unit, a traveling offset web, its rewinding mechanism, and an offset web controlling mechanism having a positively. driven roll around which the offset web passes betension tending to slightly retard the web; said reaching the printing unit and other positively driven rolls around which the offset web passes after it leaves the printing unit, to exerttension tending to slightly retard the web, said offset web controlling mechanism including a manually adjustable variable speed drive.

HOWARD M. BARBER, 

